Singer Amy Winehouse arrives at the City of Westminster Magistrates Court in central London March 17, 2009.?[Agencies]

LONDON- British singer Amy Winehouse on Tuesday denied assaulting a woman after a charity ball in London last year, a case that has already prevented her from performing in the United States.

The 25-year-old bee-hived soul singer pleaded not guilty to a charge of common assault at Westminster Magistrates' Court, the Press Association reported.

Related readings:  Amy Winehouse's home record studio  'Stupid girl' Amy Winehouse

She is accused of assaulting Sherene Flash after the Berkeley Ball last September. The case was adjourned until July 23.

The singer won five Grammy awards in 2008 and her second album "Back to Black" has won critical acclaim. But her private life, including a battle against drug addiction, has overshadowed her recording success.

Earlier this month Winehouse was unable to get a U.S. work visa to perform at April's Coachella festival in California alongside such acts as Paul McCartney and The Killers because of the assault charges.